Scientists warn of a silent rise in resistant Aspergillus and Candida

An increasing number of fungi are becoming resistant to medication, posing serious risks to patients with weakened immune systems. That’s why fifty researchers from around the world, led by Radboudumc, are calling for action against drug-resistant fungi. Their call was published in Nature Medicine.

Fungi in our environment are increasingly resistant to antifungal drugs. For healthy people this usually does not cause problems, but for those with weakened immunity these fungi can lead to serious infections. Increasing resistance makes treatment much more difficult. While global strategies against antimicrobial resistance have long focused primarily on bacteria and viruses, there is an urgent need to pay more attention to fungi.

Five step plan

Under the leadership of Paul Verweij, medical microbiologist and professor at Radboudumc, fifty researchers from sixteen organizations worked together. They gathered global data and developed a five-step plan to better monitor and prevent the emergence of resistant fungi. The publication in Nature Medicine is an important step towards updating the World Health Organization (WHO) Global Action Plan later this year. This call to action is necessary because fungal resistance still receives too little attention in current approaches. The five steps include awareness, surveillance, infection prevention and control, optimized utilization, and investment.

Fungi are everywhere

Various fungi can cause infections. Skin fungi usually lead to mild conditions such as athlete’s foot or toenail fungus. But increasingly, persistent and drug-resistant species are emerging, such as Trichophyton indotineae, which can cause severe and difficult-to-treat skin infections. In hospitals, Candida auris poses an even greater risk, as it can cause serious blood infections in vulnerable patients. One in three patients with this infection does not survive. Aspergillus fumigatus is also a concern. “We inhale this fungus and it can seriously damage the lungs,” explains Verweij. “In recent years we see it more often in ICUs, for example in people with the flu.”

Resistance to fungi does not develop in hospitals but comes largely from the environment. Fungicides used to protect crops from fungal plant diseases are very similar to antifungal drugs used in health care. Long-term exposure to agriculture allows fungi to develop resistance to these agents. These resistant fungi are then spread through the air. As a result, resistance occurring in agriculture may lead to less effective treatments for patients with severe fungal infections. The widespread use of antifungal compounds in different fields highlights the need for an integrated approach, or “One Health”.

Some new drugs

The development of new antifungal drugs is challenging. The cell structure of fungi is very similar to that of humans, much more so than that of bacteria. This means that antifungal drugs can also damage human cells, causing significant side effects. “That’s why only five new classes of antifungal drugs have been developed in the last 75 years,” says Verweij.

Because so few new drugs become available, prevention of resistance is crucial. “We need more data and evidence on fungal infections and antifungal resistance to inform and improve the response to these priority fungal pathogens,” says Haileyesus Getahun, director of WHO’s Global Coordination Program on Antimicrobial Resistance. With their new five-step plan, Verweij and his colleagues hope that countries around the world will be better prepared for this growing threat.

Quotation marks

We are facing a silent wave of drug-resistant fungi – from Candida auris in ICUs to azole-resistant Aspergillus in the community – that is already costing lives. Antifungal resistance must be integrated into the 2026 Global Action Plan for AMR, with specific milestones and funding, or we risk repeating the mistakes made with antibacterial resistance.”

Paul E. Verweij, Professor, Radboud University Medical Center

“The dual use of antifungal targets in medicine and agriculture is accelerating resistance from fields to ICUs. Aligning agricultural permits with health risk assessments while investing in new antifungals and affordable diagnostics is a realistic One Health solution that protects both food security and patient care.” said Professor Michaela Lackner, a microbiologist at the Medical University of Innsbruck.